1. Field of the Invention
Thyroxine is an important hormone in the mammalian physiology, being excreted by the thyroid gland. The measurement of thyroxine is an important diagnostic tool in the determination of disease. Various techniques have been used for the determination of thyroxine, including radioimmunoassay, competitive protein binding, chromatography, etc. These techniques suffer from a number of disadvantages in being difficult to carry out and in the case of radioimmunoassay having unstable reagents.
2. Description of the Prior Art
U.S. Pat. No. 3,817,837 describes enzyme immunoassays. U.S. Pat. No. 4,040,907 discloses iodothyronine enzyme conjugates. U.S. Pat. No. 4,171,244 discloses enzyme-bound-polyiodothyronine. A polyiodothyronine immunoassay is described in U.S. Pat. No. 4,043,872. U.S. Pat. No. 4,121,975 teaches a pretreatment of samples for polyiodothyronine assays. Enzyme immunoassays with glucose-6-phosphate dehydrogenase are described in U.S. Pat. No. 3,875,011. A method for the measurement of free thyroxine or 3,5,3'-triiodothyronine in a liquid sample is described in U.S. Pat. No. 4,410,633. Iodothyronine immunogens and antibodies are taught in U.S. Pat. No. 4,399,121. A thyroxine radioimmunoassay is described in U.S. Pat. No. 4,018,883. A radioimmunoassay for measurement of thyroxine and triiodothyronine in blood serum is disclosed in U.S. Pat. No. 3,911,096. A radioimmunoassay method for triiodothyronine and thyroxine is taught in U.S. Pat. No. 3,928,553.